涡扇发动机动态过失速数值模拟

Numerical Simulation of Post-Stall Transients in Turbofan Engine

关键词:  涡扇发动机  过失速  二维非定常  数值模拟  扰动

Key words:  Turbofan engine  Post-stall  Two-dimensional unsteady  Numerical simulation  Disturbance

摘要:

为模拟涡扇发动机的动态过失速过程，发展了一种二维非定常的数值计算方法，通过给定不同的发动机初始工作点和扰动，实现了对涡扇发动机进入、退出喘振和旋转失速过程的模拟。计算结果表明，发展的数值模拟方法能够反映出喘振和旋转失速的基本特征，可以预测喘振信号的振荡频率、强度，以及旋转失速团的传播频率和失速团沿发动机流路的发展；当旋转失速完全发展时，发动机内部各个位置处的失速团具有相同的周向传播频率，但是强度不同，发动机进、出口处的失速团信号最弱，压缩部件进口和低压涡轮出口处的失速团信号最强。

Abstract:

A two-dimensional unsteady numerical method has been performed to simulate the post-stall transients in turbofan engine. By assigning different initial work points and different types of disturbances，the process of the turbofan engine stepping in and out of surge or rotating stall was simulated. The results of numerical computation indicate that the new method can simulate the basic features of surge and rotating stall. It can be used to predict the oscillation frequency and intensity of surge signal，also the propagating frequency and the development in engine flow path of the rotating stall cell. When the rotating stall is fully developed in the engine，the stall cells all over the engine share the same circumferential propagating frequency，while their intensity is different. The stall cells at the inlet and outlet of the engine are weak，while the stall cells at the inlet of the compressors and the outlet of the low pressure turbine are strong.